Thanks RC for information on hand-level; he has recommended it in his "Instructions" ["Geology", Collected papers 1: 227–50].

Transcription

Down Farnborough Kent

Monday

My dear Sir

I just send one line to thank you very much for the trouble you have taken in sending
me the account of the Hand-level, which I have recommended in my
Instructions.— I am delighted to hear what
progress your Book has made; I had no idea you were going to
publish so grand an affair as 30 engravings sounds like. I am glad you are
prepared to fight stoutly with the sceptical geologists.

The period during which CD worked on the geology chapter of Herschel ed.
1849.

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f2 1160.f2

CD discussed the use of the hand-level in surveying in Herschel ed. 1849,
p. 161 (Collected papers 1: 230), and described an instrument, sold by
Adie and Son of Edinburgh: ‘Mr. R. Chambers, moreover, and others
have found, that an observer having previously ascertained the exact height of his eye
when standing upright, can measure the altitude of any point with surprising
accuracy’.

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f3 1160.f3

Chambers 1848.

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f4 1160.f4

Chambers defended the view that large areas of Scotland been submerged and that the
‘parallel roads’ in the present glens were ancient sea beaches. To
account for the change he maintained that the sea had receded; CD had suggested an
elevation of the land (‘Observations on the parallel roads of Glen
Roy’, Collected papers 1: 89–137). See letter to Charles
Lyell, [16 June 1848], for CD's comments on Chambers 1848.